Samba printing: Held for authentication

On my Fedora systems, I have added a shared printer, but print jobs just get “Held for authentication”.

The printer is shared on the network over samba. It is connected by USB to a Windows 7 machine.

The right click menu of the print queue dialog has “Release” which does nothing. There is also “Authenticate”, which asks for username and password. I don’t know what credentials are required. I tried the (Windows) host user’s credentials, and my (Fedora) client’s but neither worked.

/etc/cups/printers.conf contains “AuthInfoRequired none” for the printer.